Three Monitors - One real Video Card?

[matthewtoney]

Anybody used one of the USB-DVI or USB-VGA that has Mac support and can comment on it, or know any other way to drive three monitors with only one real video card?

I ask since everything seems to point to combining two cards in your Pro with one being Nvidia and one being ATI to be a *bad* thing when it comes to certain things.

(I'd really like to keep my 4870 - I want at least one good-performance card rather than running something like 2 GT120's, and the Mac GTX285 is just crazy expensive)

 

[skunkworker]

You could look at a cheaper ATi 2600 XT for mac pro. As long as you aren't running anything really intensive that should work.

 

[TheStrudel]

Used card on eBay, maybe.

Alternatively, one could try flashing some of the newer PC 4870 cards with three display outputs, but none of them have 3 DVI ports and we haven't had any luck getting non-DVI ports to work.

 

[aliot]

well,you could look at some "USB videocard".I'm not sure do they working on mac os,but you can try.

like this
http://www.everythingusb.com/iogear_usb_2.0_external_video_card_12787.html

 

[matthewtoney]

You could look at a cheaper ATi 2600 XT for mac pro. As long as you aren't running anything really intensive that should work.

Doesn't the 2600XT require a power connector as well? (maybe I'm wrong on that)

well,you could look at some "USB videocard".I'm not sure do they working on mac os,but you can try.

like this
http://www.everythingusb.com/iogear_usb_2.0_external_video_card_12787.html

Yeah I've found one out there that *does* support OSX, but it's as much as a lot of video cards - I wouldn't want to try it without hearing from someone who had already done so.

Used card on eBay, maybe.

Alternatively, one could try flashing some of the newer PC 4870 cards with three display outputs, but none of them have 3 DVI ports and we haven't had any luck getting non-DVI ports to work.

I didn't even realize that there were any with 3 outputs. I'm using an XFX flashed 4870 (with dual DVI) now and it works great - it's the combining it with the GT120 that came with the Pro that's the trouble

 

[TheStrudel]

The 2600, like the 120, does not require additional power. Just power provided by the PCIe slot.

 

[matthewtoney]

The 2600, like the 120, does not require additional power. Just power provided by the PCIe slot.

Sounds like the 2600 is the best candidate to replace the GT120 then at this point, and I know they can be had for not a ton of bucks. I know the 2600 doesn't do OpenCL - does that matter when my other primary card does?

 

[Sharangad]

Sounds like the 2600 is the best candidate to replace the GT120 then at this point, and I know they can be had for not a ton of bucks. I know the 2600 doesn't do OpenCL - does that matter when my other primary card does?

The upcoming Radeon HD 5000 series supports between 3-6 monitors (6 with 6 mini-displayports, 3 with two DVI, 1 HDMI and 1 DisplayPort of which anyone can be active) on one card. You could wait for the next version.

http://www.youtube.com/watch?v=mzGtxlaPQqY

 

[matthewtoney]

The new Radeon 5000 series sounds awesome, but whos knows when or IF there will be a Mac version - I think that's a hard thing to count on as being my solution.

I'm thinking a cheap 2600XT to replace to GT120 would work, but I'd love to know how an OpenCL supporting app works in a system with one video card with OpenCL support and one card without it.

 

[TheStrudel]

I don't see why not. The way OpenCL is supposed to work is that it queries your system for all devices that support OpenCL and dynamically attaches them to processing jobs as needed. So it'll hit your primary card and ignore non-compatible cards. Don't know whether or not it'll tap extra OpenCL supporting cards as well.

That said, there are no OpenCL apps yet so we don't know if multiple graphics cards will work in such a situation, etc.

 

[netkas]

opencl should have no problems